1. Field of the Invention
The present invention relates to a surface fastener member, a surface fastener combined with the same surface fastener member and a product attached with the same surface fastener or the like and more particularly to a noiseless surface fastener member capable of reducing a noise generated when it is separated, a combination thereof and a product attached with the surface fastener capable of reducing the noise occurring when the same surface fastener is separated.
2. Description of the Prior Art
In a fiber surface fastener, bold fiber-like monofilaments or strings each composed of multiple narrow fiber-like filaments (multifilaments), both of which are made of synthetic resin, are woven or knitted into a base material obtained by weaving or knitting various kinds of fiber yarns so as to form loops on one side of the base material. The monofilament loops are partially cut out so as to form hook-shaped male engaging elements while the multifilament loops form female engaging elements just with that loop configuration. The male engaging element and the female engaging element engage each other when pressure is applied and if a force is applied to both elements in a separation direction, the engagement is released so that they are separated from each other. In a molded surface fastener of synthetic resin as well as the fiber surface fastener having such a structure, a noise offensive to the ear is generated when the male and female engaging elements are disengaged.
Conventionally, a number of fiber surface fasteners aiming at suppressing such noise have been proposed. Examples disclosing relating noiseless structures are, for example, U.S. Pat. Nos. 4,776,068 and 4,884,323.
In the sound deadening structure of the fiber surface fastener disclosed in the U.S. Pat. No. 4,776,068, the surface fastener member, which is a surface fastener component, has means for reducing a complex of noise and vibration given by the planar base material thereof to surrounding space. This means reduces a noise generated when the surface fastener member is quickly separated from a mating joint face. This means comprise forming the base material with a larger volume than the engaging face, joining a planar large-volume auxiliary base material to the base material, incorporating flexible large-volume material in the base material, forming the base material and the engaging face separately while connecting these components at multiple points, employing a grid structure for the base material in order to lower a transmission capacity of vibration in surrounding spaces.
More specifically, a grid structure having a porosity of 50% or more, which indicates a low transmission capacity for vibration in a space surrounding the base material, is employed so as to reduce a complex of noise and vibration generated when the surface fastener members are separated from each other. Further, in such a surface fastener, the sound level measured at a position apart by 1 feet from that separation area needs to be a specified value or less. Alternatively, engaging faces of each planar base material are provided separately in an extending manner and a layer having an air density is formed on the rear face of the base material so as to increase its volume. Consequently, the level of sound pressure generated when the surface fastener is separated can be reduced sufficiently to 4.2 dB or less.
Meanwhile, according to U.S. Pat. No. 4,884,323, in a product attached with the surface fastener member, a flat base material having the engaging elements on a face thereof is attached such that the rear surface thereof is apart from the product. Consequently, the noise-generation energy transmitted from the base material to the product when the engaging surface fastener members are separated is reduced, so that the noise generated from the product can be reduced. Alternatively, a large-volume material is attached to the rear surface of the product, and even if noise energy is transmitted to a member, the energy is damped by the large-volume material attached to the rear surface of the product. That is, according to the surface fastener attaching system of U.S. Pat. No. 4,884,323, an intermediate member is interposed between the base material and the product or large-volume member with a low density is attached to the rear surface of the product to be attached to the base material. When the intermediate member is used, it is attached to the base material and the product by coupling their edge portions. A grid-like base material having the same structure as above-mentioned U.S. Pat. No. 4,776,068 can be adopted as the base material.
In the noiseless surface fastener disclosed in U.S. Pat. No. 4,776,068, both of the base materials of the surface fastener members to be joined together need to be in a grid-like form, though, in this kind of the surface fastener used in various fields, its mating components need to be in various forms. For example, when a grid-like base material is used, engaging elements which constitute an engagement face formed on one face of the base material are arranged also in a grid-like form, so that the engagement ratio and engagement strength necessarily drop. Moreover, when the base material is in a grid-like structure, not only the strength the base material is diminished but also a high sewing accuracy is required.
In the attachment system for the surface fastener member according to U.S. Pat. No. 4,884,323, because the surface fastener member is attached only at their edge portions. In addition, there is no element for fixing the surface fastener member to the cloth at the central portion of the surface fastener member. Therefore, this system is not suitable for attachment of a wide surface fastener. Further, interposing a large-volume material between the base material of the surface fastener member and the cloth results in such a disadvantage that the sewing method becomes complicated thereby increasing the number of production steps. In order to obtain enough effects with this method, the capacity of vibration absorption agent needs to be increased sufficiently. As a consequence, a fastener attachment portion of the product needs to be thick.
In the meantime, Japanese Patent Application Laid-Open No. 6-103 discloses a surface fastener having vibration absorption material on a rear surface of its base material. In order to obtain a sufficient performance with this method, the vibration absorption agent needs to be heavy enough, thereby causing such a disadvantage that the surface fastener becomes thick. Moreover, although these technologies aim at suppressing the magnitude of a separation noise, some sounds are offensive to the ear, while the others are not. Therefore, just reducing the sound level is not sufficient, and it is important not to generate sounds which are offensive to the ear.
A relatively large abnormal sound generated upon separation of the surface fastener occurs when the base material is vibrated. The sound damping structure disclosed in the aforementioned publication aims at reducing the vibration area of the base material so as to reduce vibration itself transmitted from the base material to the air. In this structure, when the surface fastener is attached to a product, the vibration is transmitted directly to the product, and complex vibration due to the vibration of the product itself is transmitted to the air, thereby generating a large noise. Consequently, sufficient effects cannot be obtained. Further, if an intermediate member or vibration absorption member is provided separately on the rear surface, sewing or bonding labor doubles, thereby increasing the cost.
The above-mentioned publication of the prior art aims at reducing the noise generated with a method of reducing the ratio of the base material vibration transmitted to the air. However, when the surface fastener is attached on an attachment object, the vibration of the surface fastener base material is transmitted to the attachment object, accompanying radiation of the sound from the attachment object. Thus, sufficient sound-damping effects cannot be obtained. Also, when a mounting member or vibration absorption material is provided on the rear surface of the surface fastener, its entire structure becomes thick, and if this fastener is employed for clothing, it becomes bulky and the texture of the clothing is deteriorated.
Furthermore, when the surface fastener member is attached by sewing, the vibration upon separation is transmitted to the object attached with the surface fastener, and noise is generated also from the attachment object. Therefore, the sound damping effect is not achieved sometimes even if the noise generated from the surface fastener itself is reduced.